Bragging about yourself, talking about your own accomplishments, talking about how much money you have or how good you are at sporst, how smart you are, how much god loves you, giving advice to others as if you are the top dog, etc.

Especially used when done not in-person, but through Facebook or Twitter, thus broadcasting the brag not at one person, but to everyone.

Did you see his status update "Private planes help me travel in peace, to 4 cities in one day and 4 countries in one week." Talk about douchebragging!